Low-water alarm



J. G. TALMAGE.

LOW WAT ER ALARM. APPLICATION FILED JUNE 11. 1920.

1,405,953, Patented Feb. 7, 1922.

mvzmoR ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN G. TALMAGE, OF CLEVELAND, OHIO, ASSIGNOR TO HERMAN B. THURSTON, OF

PITTSBURGH, PENNSYLVANIA.

Low-WATER ALARM.

Specification of Letters Patent.

Patented Feb. '7, 1922.

T 0 all whom it may concern:

Be it known that I, JOHN G. TALMAGE, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Low-VVater Alarms, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings.

My invention relates to low water alarms of the type wherein a fusible element nor mally closes a steam pipe leading to an alarm signal, the fusible member under sufficient increase in temperature melting and allowing the alarm to operate. One of the objects in my invention is to provide, in a low water alarm of the type which may be applied to the crown sheet of boilers and operate to sound a whistle upon thewater falling below a predetermined level, a positive closure for the steam line leading to said whistle so that under no conditions save that of excessive temperature may any steam escape.

A further object of the invention is to .provide a socket member having a plug disposed therein with a bore normally filled with readily fusible material, the plug being threaded to the socket member by tapering threads whereby a tight fit is assured, thereby allowing said plug to be removed and replaced repeatedly as desired, without causing liability of leaks.

A further object of the invention is to provide a device which is simple and can be cheaply made andwhich is highly efficient in use.

In the accompanying drawings, wherein my invention is illustrated, Fig. 1 is a side elevation partly broken away showing a boiler equipped with my low water alarm; Fig. 2 is an elevation of the socket member, the internal threads being shownin dotted line position; Fig. 3 is a section on the'line 33 of Fig. 2, the plugs being shown in position; Fig. i is a plan and elevation of the plug containin a fusible material and Fig. 5 is a plan an elevation of'the closure for the bottom of the socket member.

Referring to thedrawings, a boilerofany suitable type is shown at 1, the crown sheet being indicated at 5. A socket member 2 is shown'as connected to a pipe 4, a whistle 6 being connected to said ipe as shown. The socket member, generally indicated at 2,

her is a series of apertures 14, here shown as cruciform in arrangement, which afford communication with the exterior of the socket. A passage 16 is shown as extending from the chamber. 11, which passage may terminate in a tapering thread 17to which steam pipe l, Fig. 1 is shown to be threaded.

A plug 20 having a wrench engaging portion 21 is shown as closing the lower end of the channel 16, the plug being indicated as provided with a tapering thread 22 to fit a similar thread in the wall of the casing 2. A tapering bore-24: is shown as provided in the plug 20 and within this bore the fusible material 26 is placed. It willbe noted that communication through the apertures 14, with the chamber 11 and channel 16 is open when the plug 20 is not in place. The latter, however, in position closes such communication and it is'only after the fusible material has melted that communication is opened.

The provision of tapering threads assures the tight fit of all connections at all times and does away with the difliculty'experienced in former types of low water alarms which were very apt to leak, especially if it is necessary to remove and replace the parts. By my invent-ion the use of tapering threads insures tight joints and takes up any wear occasioned by the removing or replacement of the parts. To renew the fusible element, the plug 9 may be removed from within the fire box; then the plug 20 may be unscrewed and a new plug carrying a fusible element readily inserted and caused to make a tight fit by reason of the tapered thread 22 then the plug9 is replaced.

In operation, when the water falls to a dangerous level the heat at the top of the crown sheet will be transmitted to the fusible material, which thus melts and flows from the plug20, or will be blown out by the steam pressure, thereby opening communication between the boiler the whistle, causing the latter to sound, I

Having thus described my invention, I claim:

1. A hollow socket member having two internal threads, and having a chamber between said threads, an aperture extending through the wall of the socket member to said chamber, two aligned plugs, each engagin one thread, said chamber extending. to sald plugs, one of said lugs having a dis charge opening and fusi le material in said opening, said aperture communicating with the exterior of the member and with the interior of a boiler, and the other plug closing communication with the firebox.

2. A hollow socket member having two internal threads, and having a chamber between said threads and an aperture communicating with the interior of a boiler, said aperture extending through the wall of the socket member to said chamber, and two aligned plugs, each engaging one thread and forming a steamtight connection with the socket member, said chamber communicating with said plugs, one of said plugs having a discharge opening and fusible material in said opening.

3. A hollow socket member having two internal threads, and having a chamber between said threads, an aperture extending through the wall of the socket member to said chamber and twoplugs, each engaging one thread, said chamber extending to said plugs, one of said plugs having a discharge opening and fusible material in said opening, said last mentioned plug being smaller than the other plug, said chamber having openings communicating with the exterior of the member and closed bythe plugs re-. spectively, one of said openingsbeing large enough to allow passage of the largest plug whereby both plugs are removable through said opening.

4. A hollow socket member having two internal threads and having a chamber intermediate said threads, an aperture extending through the wall of the socket member to said chamber, two plugs, each engaging one thread, whereby said plugs serve to close said chamber a discharge conduit communi eating with said chamber through a passageway in one of the plugs, and fusible means closing said passageway.

5. The combination of a tubular hollow socket member having a chamber intermediate-its ends and apertures leading from said chamber to the external surface thereof,

the ends-0f said socket member being pro-' vided with internal tapering threads, tapermg threads adjacent the intermediate p0rtion of said socket member, a plug having a central bore threaded to said last mentioned thread, fusible material in said bore with WhlCh said chamber communicates, and a plug threaded in the end of said socket member.

7. In combination with the crown sheet of a boiler, a hollow socket member secured to said crown sheet, a pipe leading from one 7 end of said socket to a whistle, a plug secured to the other end of said socket member to close the same, whereby communication is closed between the chamber and fire box, a second plugthreaded by tapering threads intermediate the ends of said socket and provided with a bore containing fusible material, said socket member having a chamber between said plugs, extending to them, and havin an aperture leading from the external sur ace to the chamber and communicating with the interior of the boiler.

8. The combination of a tubular socket member, an aperture leading from the in terior to the exterior thereof, the ends of said socket member being provided with internal tapering threads, tapering threads adjacent the intermediate portion of said socket member, a thermal'plug threaded to said last mentioned threads and adapted to be affected by heat to open the passageway, and a plug threaded in one end'of said socket member.

9. In combination, a socket member com prising a tubular body open at each end, internal threads adjacent one end of said tubular body, a central portion of said socket member being reduced in external diameter, and having tapering internal threads adjacent said reduced portion, all of said hereinbefore mentioned threads tapering'one direction, a chamber between said threads having an opening extending laterally through the walls of the member and plugs engaging said threads respectively and closing the ends of said chamber. r

10. In combination, a socket. member comprising a tubular body open at each end, ex ternal and internal threads adjacent one end of said tubular body and adjacent each other, a central portion of said socket memher being reduced in external and internal diameter, and having tapering internal threads adjacent said reduced portion, all of said hereinbefore' mentioned threads tapering one direction, a chamber between said threads having a' lateral opening; through the walls of said member and plugs engaging said threads respectively to close the ends of said chamber.

11. Asocket member comprising a tubular body, external and internal threads adjacent one end of said tubular body and adjacent each other, a central portion of said socket member being reduced in external and internal diameter, and having tapering internal threads adjacent said reduced portion, all of said hereinbefore mentioned threads tapering one direction, the other end being further reduced in diameter and provided with in ternal threads tapering in a direction opposite to the taper of said first mentioned threads.

12. In combination with a crown sheet of a boiler, a socket member comprising a tubular body portion having channels therein closed by two plugs, one channel leading to a signal and the other leading to a fire box, one of said plugs being fusible, and an intermediate open channel communicating with the interior of the boiler and with the interior of said tubular body portion intermediate of the plugs.

In testimony whereof, I hereunto affix my signature.

JOHN G. TALMAGE. 

